Method of filling a mould and system for filling a mould

ABSTRACT

Method of filling a mold with a glass gob through an opening of the mold, for forming a glass product in the mold, by using a delivery system for delivering the glass gob to the opening of the mold. The delivery system has an inlet, an outlet, and guiding means for guiding the glass gob through the delivery system. The method includes observing the glass gob, at at least one moment and/or during at least one period after the glass gob has passed the inlet of the delivery system, by using an optical imaging device. The method includes determining a glass gob observation result that includes a glass gob velocity, for predicting a glass distribution of the glass product formed in the mold and/or for controlling a next glass gob.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/125,082 having a filing date of Oct. 21, 2008 and which is a 371 ofPCT/NL2008/050660 filed Oct. 21, 2008.

A portion of the disclosure of this patent document contains materialthat is subject to copyright protection. The copyright owner has noobjection to the reproduction of the patent document or the patentdisclosure, as it appears in the U.S. Patent and Trademark Office patentfile or records, but otherwise reserves all copyright rights whatsoever.

BACKGROUND OF THE INVENTION

The invention relates to a method of filling a mould with a glass gobthrough an opening of the mould, for forming a glass product in themould, by using a delivery system for delivering the glass gob to theopening of the mould, the delivery system having an inlet, an outlet,and guiding means for guiding the glass gob through the delivery system,the method including the steps: a) depositing the glass gob in the inletof the delivery system; b) guiding the glass gob by using the guidingmeans towards the outlet of the delivery system; c) depositing the glassgob from the outlet of the delivery system in the opening of the mould.The invention also relates to a system comprising an optical imagingdevice, a signal processing unit coupled to the imaging device, and anapparatus for filling a mould with a glass gob through an opening of themould, for forming a glass product in the mould, the apparatus having adelivery system for delivering the glass gob to the opening of themould, the delivery system having an inlet, an outlet, and guiding meansfor guiding the glass gob through the delivery system towards the outletof the delivery system.

BRIEF SUMMARY OF THE INVENTION

Glass gobs are used for manufacturing glass products such as bottles.Glass gobs are usually formed from a glass reservoir, and subsequentlyguided to the mould by means of the guiding structure. In practicalapplication of a glass product manufacturing process, it accidentallyhappens that bottles are misshaped or are otherwise unacceptable,resulting from erroneous filling of the mould. In such a situation, theproduction process has to be adjusted, which may even require stoppingof the production process. A cause for the erroneous filling is oftenunclear, so that adjusting the production process takes place by trialand error. Such a way of process control is inefficient and can berather costly.

Accordingly, it is an object of the invention to provide a method forfilling a mould with a glass gob that enables improved process control.

Thereto the invention provides a method of filling a mould with a glassgob through an opening of the mould, for forming a glass product in themould, by using a delivery system for delivering the glass gob to theopening of the mould, the delivery system having an inlet, an outlet,and guiding means for guiding the glass gob through the delivery system,the method including the steps: a) depositing the glass gob in the inletof the delivery system; b) guiding the glass gob by using the guidingmeans towards the outlet of the delivery system; c) depositing the glassgob from the outlet of the delivery system in the opening of the mould;d) observing the glass gob, at at least one moment and/or during atleast one period after the glass gob has passed the inlet of thedelivery system, by using an optical imaging device, and e) determining,based on the observing in step d), a glass gob observation result thatincludes a glass gob velocity, for predicting, based on at least theglass gob velocity of the glass gob observation result, a glassdistribution of the glass product formed in the mould, and/or forcontrolling, based on at least the glass gob velocity of the glass gobobservation result, depositing as in step a), guiding as in step b),and/or depositing as in step c), of a next glass gob that is formedlater than the glass gob. Preferably, the glass gob velocity includes amagnitude of the glass gob velocity and/or a direction of the glass gobvelocity. Preferably, the glass distribution includes an internalstructure and/or an external shape of the glass product formed in themould. The internal structure may refer to inclusions within glassmaterial of the glass product. The external shape may refer to, atvarious locations along the glass product, length dimensions of theglass product, such as an inner diameter and an outer diameter of theglass product. It was recognized by the inventor that minimizing loss ofglass gob velocity when the glass gob travels through the deliverysystem, is important for forming a correctly shaped and/or correctlystructured glass product in the mould. If the magnitude of the glass gobvelocity is too low, the glass gob may not be able to travel far enoughinto the mould. As a result, the external shape of the glass product maydeviate from the predetermined external shape. The predeterminedexternal shape for example is a shape of a surface of the glass productwithin normal manufacturing specifications. If the direction of theglass gob velocity is not directed centrally into the mould opening,friction between the glass gob and an inner wall of the mould may becometoo large for part of the glass gob. As a result, gas may be included inthat part of the glass product, for example in the form of gas bubbles.Such gas inclusion may for example result from entrapped air, or fromevaporated entrapped lubricant of the mould. Gas inclusion in general isunwanted, as it may decrease a strength of the glass product. If thefriction is too large, the degree of inclusion of gas in the glassproduct may be too large. The degree of inclusion of gas is an exampleof the internal structure of the glass product. The inventor realizedthat the friction being too large may also lead to asymmetric heat lossof the glass gob in the mould, which may result in an asymmetricviscosity of the material of the glass gob and as a result to anasymmetric external shape of the glass product. The degree of inclusionof gas in the glass product and the deviation of the shape of the glassproduct from the predetermined shape are examples of important qualityparameters for the glass product. As the glass gob velocity thus is animportant variable, determining the glass gob velocity for predictingthe glass distribution and/or for controlling a process step of the nextglass gob, enables improved process control.

Preferably, step e) includes predicting, based on at least the glass gobvelocity of the glass gob observation result, a glass distribution ofthe glass product formed in the mould, and/or controlling, based on atleast the glass gob velocity of the glass gob observation result,depositing as in step a), guiding as in step b), and/or depositing as instep c), of a next glass gob that is formed later than the glass gob.

Predicting and/or controlling in step e) may be based on a predeterminedrelation between the glass gob velocity and the glass distribution ofthe glass product formed in the mould. Such a predetermined relation maycouple different reference glass gob velocities to different forms ofthe glass distribution, for example to probabilities for obtainingdifferent forms of the glass distribution. By comparing the determinedglass gob velocity with the reference velocities, a correspondingprobability for obtaining a form of the glass distribution may beidentified. A prediction for the glass distribution can then be made,and/or a process step for the next glass gob can be adjusted. In apractical variation of the method, predicting in step e) may be carriedout by comparing the magnitude of the glass gob velocity with a limitvalue, wherein the magnitude of the glass gob velocity should be abovethe limit value for preventing an undesirable high probability for amisshaped and/or misstructured glass product. In this variation, thepredetermined relation may include a range of velocities lower than thelimit value, with corresponding thereto an undesirable high probabilityfor a misshaped and/or misstructured glass distribution, and/or a rangeof velocities larger than the limit velocity, with an acceptableprobability for a well-shaped and/or well-structured glass distributioncorresponding thereto. The predetermined relation and/or the limit valuemay be determined by trial and error. Analogously, predicting in step e)may be carried out by comparing the magnitude of the glass gob velocitywith another limit value, wherein the magnitude of the glass gobvelocity should be below the other limit value for preventing anundesirable high probability for a misshaped and/or misstructured glassproduct.

Alternatively or additionally, predicting and/or controlling in step e)may be carried out by using a self-learning algorithm, having input andoutput variables. Such self-learning algorithms as such are known to theskilled person. The velocity and the glass distribution may be used asinput variables. A prediction signal and/or a controlling signal may beused as output variables, arranged for respectively predicting and/orcontrolling in step e). Based on the input signals obtained underinfluence of earlier output signals, the self-learning algorithm mayadapt itself to for example improve determination of a probability for amisshaped and/or misstructured glass distribution. The algorithm may, inuse, adapt its parameters if predicted glass distributions deviate fromthe glass distributions that are actually realized.

In yet another variation, predicting, based on at least the glass gobvelocity of the glass gob observation result, the glass distribution ofthe glass product formed in the mould, as carried out in step e), isinterpreted as assessing, based on at least the glass gob velocity ofthe glass gob observation result, the glass distribution of the glassproduct formed in the mould.

Step a), b), c), d), and e) may be applied in that order, although thisis not necessary.

In an embodiment, predicting the internal structure in step e) includespredicting the degree of inclusion of gas in the glass product and/orpredicting the external shape in step e) includes predicting thedeviation of the external shape of the glass product from apredetermined external shape. Such predicting may be based on apredetermined relation between the glass gob velocity and the degree ofinclusion of gas in the glass product, and/or on a predeterminedrelation between the glass gob velocity and the deviation of theexternal shape of the glass product from the predetermined externalshape.

Preferably, the glass gob velocity includes the magnitude of the glassgob velocity, and predicting the deviation of the external shape of theglass product from the predetermined external shape is based on themagnitude of the glass gob velocity. If the magnitude of the glass gobvelocity is too low, the glass gob may not be able to travel far enoughinto the mould, so that the shape of the glass product will deviate fromthe predetermined shape. Preferably, the glass gob velocity includes thedirection of the glass gob velocity, and predicting the degree ofinclusion of gas in the glass product and/or predicting the externalshape of the glass product is based on the direction of the glass gobvelocity. If the friction is too large, the degree of inclusion of gasin the glass may be too large, and/or the glass gob may not be able totravel far enough into the mould. The friction being too large may alsolead to asymmetric heat loss of the glass gob in the mould, which mayresult in an asymmetric viscosity of the material of the glass gob andas a result to an asymmetric external shape of the glass product.

Preferably, determining the glass gob velocity in step e) includesdetermining both the magnitude and the direction of the glass gobvelocity. However, determining the magnitude of the glass gob velocitywithout determining the direction of the glass gob velocity, ordetermining the direction of the glass gob velocity without determiningthe magnitude of the glass gob velocity, is also valuable.

Optionally, the magnitude of the glass gob velocity at least includes anarrival time of the glass gob at an observation position after the inletand optionally after the outlet. Optionally, the direction of the glassgob velocity at least includes a position of the glass gob near theobservation position after the inlet and optionally after the outlet.These options, on itself and in combination, represent rather simple butefficient ways of determining the glass gob velocity. However, it may beclear that other ways of determining the glass gob velocity may give abetter and more reliable result, for example determining the glass gobvelocity, by using the optical imaging device, based on images of oneand the same glass gob taken at at least two different times and twodifferent positions of the one and the same glass gob. Therefore, theglass gob velocity may lack the glass gob position and/or the arrivaltime.

In an embodiment, the glass gob observation result further includes atleast one variable of a glass gob trajectory, a glass gob shape, achange in the glass gob shape, a glass gob orientation, and a change inthe glass gob orientation, wherein predicting and/or controlling in stepe) is further based on the at least one variable. Such a variable, orsuch variables, additional to the glass gob velocity, enable a betterprocess control. Without negating the usefulness of the other variables,in particular determining the glass gob shape is useful. The shape ofthe glass gob can change while it falls from the outlet to the openingof the mould, or can change while the glass gob travels along theguiding means. For correct filling of the mould, it is desired that theglass gob has a correct shape when it enters the opening of the mould.

In an embodiment, observing in step d) is carried out at at least onemoment and/or during at least one period after the glass gob has, atleast partly and optionally completely, passed the outlet of thedelivery system. In this way, the glass gob observation result isrepresentative for the distribution process of the glass gob in themould.

In an embodiment, observing in step d) is carried out at at least onemoment and/or during at least one period before the glass gob has,completely and optionally at least partly, entered the opening of themould. Preferably, observing is carried out with the glass gob beingpositioned in proximity of the mould, preferably within one, two, orthree times a dimension, such as a maximum or minimum diameter, of theglass gob. The maximum diameter may be directed along a longitudinalaxis of the glass gob in case the glass gob has an elongated shape, andthe minimum diameter may be directed transverse to the longitudinalaxis. The closer the glass gob is observed near the mould opening, themore the observation result is representative for the distributionprocess of the glass gob in the mould.

In an embodiment, observing in step d) is carried out at at least onemoment and/or during at least one period after the glass gob has, atleast partly, entered the opening of the mould. After entering of themould, there is a fair chance that the glass gob makes mechanicalcontact with an inner side of the mould. If the friction of the glassgob with the inner side of the mould is too large, this will result in adecrease in the glass gob velocity. Therefore, determining the glass gobvelocity, in particular the magnitude of the glass gob velocity, afterthe glass gob has entered the opening of the mould enables predictingand/or controlling in step e), based on a direct observation of thefilling process in the mould.

In an embodiment, the method includes aligning the optical imagingdevice with respect to the mould. This enables relating the glass gobobservation result, in particular the direction of the glass gobvelocity, to a location of the opening of the mould.

In an embodiment, the optical imaging device includes at least twocameras, each camera having an optical axis, wherein observing in stepd) is carried out with the optical axes of the at least two camerashaving mutually distinct directions, preferably mutually transversedirections. The use of two cameras enables three-dimensional observationin step d), for example observing a three-dimensional glass gobvelocity. Preferably, the optical axes of the at least two cameras aredirected transverse to a travel path of the glass gob from the outlet tothe opening of the mould. In this way, accuracy of the determination ofa three-dimensional glass gob velocity is increased.

In an embodiment, the glass gob velocity is a three-dimensional glassgob velocity. This enables a more reliable process control. Preferably,the glass gob velocity includes a three-dimensional direction of theglass gob velocity. This enables determination of a three-dimensionaltrajectory of the glass gob.

In an embodiment, the glass gob trajectory is a three-dimensional glassgob trajectory, the glass gob shape is a three-dimensional glass gobshape, the change in the glass gob shape is a change in thethree-dimensional glass gob shape, the glass gob orientation is athree-dimensional glass gob orientation, and the change in the glass goborientation is a change in the three-dimensional glass gob orientation.

In an embodiment, the method includes the steps: f) forming the glassgob, by detaching the glass gob from a liquid glass reservoir; and g)using the glass gob observation result for controlling forming the nextglass gob that is formed later than the glass gob formed in step f).Forming of the glass gob may be achieved by known methods, such as usingshear blades to detach the glass gob from a glass column pushed out of areservoir of liquid glass. Step f) may be carried out before step a).Step g) may be carried out after carrying out step d), optionally aftercarrying out step e).

In an embodiment, controlling in step g) is based on at least the glassgob velocity of the glass gob observation result and/or is based onpredicting, in step e), the glass distribution of the glass productformed in the mould.

In an embodiment, controlling in step e) is further based on predicting,in step e), the glass distribution of the glass product formed in themould.

In an embodiment, controlling, in step e), of guiding as in step b) ofthe next glass gob includes adjusting lubrication of the guiding means.Variation in the glass gob velocity may be related to variation inlubrication of the guiding means. Thus, a decrease in the glass gobvelocity may be counteracted by adjusting, in this case increasing,lubrication of the guiding means.

In an embodiment, controlling, in step e), of depositing as in step a)of the next glass gob includes adjusting a mutual position difference ofthe inlet and a formation position at which the glass gob is formed.Preferably, controlling, in step e), of depositing as in step c) of thenext glass gob includes adjusting a mutual position difference of theoutlet and the opening of the mould. Adjusting, based on the glass gobobservation result, the mutual position difference of the inlet and theformation position at which the glass gob is formed, enables improvedprocess control of depositing the next glass gob in step a). Adjusting,based on the glass gob observation result, the mutual positiondifference of the outlet and the opening of the mould, enables improvedprocess control of depositing the next glass gob in step c).

In an embodiment, the guiding means include a scoop funnel forming theinlet, a trough, and a deflector funnel forming the outlet, whereinguiding the glass gob in step b) includes guiding the glass gob by meansof the scoop funnel towards the trough, and further includes guiding theglass gob by means of the trough towards the deflector funnel, andwherein depositing the glass gob in step c) includes depositing theglass gob by means of the deflector funnel in the opening of the mould,wherein controlling, in step e), of guiding as in step b) of the nextglass gob includes adjusting a mutual position of at least two of thescoop funnel, the trough, and the deflector funnel. Adjusting, based onthe glass gob observation result, the mutual position of the at leasttwo of the scoop funnel, the trough, and the deflector funnel enablesimproved process control of guiding as in step b) of the next glass gob.For example, a resistance for the next glass gob at the transition fromthe scoop funnel to the trough can be changed, preferably decreased, byadjusting the mutual position of the scoop funnel and the trough. Forexample, a resistance for the next glass gob at the transition from thetrough to the deflector funnel can be changed, preferably decreased, byadjusting the mutual position of the trough and the deflector funnel.

It may be clear that controlling deposition of the next glass gob instep a) and controlling guiding the next glass gob in step b) add tominimizing loss of glass gob velocity when the next glass gob travelsthrough the delivery system.

In an embodiment, predicting in step e) includes comparing the glass gobvelocity with a previous glass gob velocity of a previous glass gob thatis formed earlier than the glass gob, wherein a difference between thepredicted glass distribution in the mould and a previous glassdistribution in the mould of the previous glass gob, depends on adifference between the glass gob velocity and the previous glass gobvelocity. The predetermined relation and/or the input of theself-learning algorithm may be based on the previous glass gob velocityand/or on the previous glass gob distribution in the mould.

In an embodiment, controlling, in step e), of depositing as in step a)of the next glass gob includes adjusting air supply to an acceleratorfor the next glass gob, which accelerator is positioned before theinlet. The accelerator may be arranged for increasing the magnitude ofthe glass gob velocity before it enters the inlet. Therefore, thisembodiment enables an efficient way of adjusting the velocity of thenext glass gob.

In an embodiment, the method includes repeating steps a)-e) for aplurality of glass gobs, wherein predicting in step e) includescomparing between the plurality of glass gobs the glass gob observationresult determined in step e). Comparing may be between glass gobsdeposited at different positions, preferably from different deflectorfunnels. Such process control supports uniformity of glass products madefrom the glass gobs. Alternatively or additionally, comparing may bebetween glass gobs deposited at the same position, preferable from theone of the scoop funnels. This supports the process control in thatdifferences, for example changes in time, in the glass gob observationresult can be detected from one glass gob to another glass gob.

In an embodiment, the glass gob is substantially made of inorganicmaterial such as silicon oxide.

More in general, it may apply that the method relates to a first step ofobserving the glass gob, at at least one moment and/or during at leastone period after the glass gob has passed the inlet of the deliverysystem, by using an optical imaging device; and to a second step ofdetermining, based on the observing in the first step, a glass gobobservation result that includes a glass gob velocity, for predicting,based on at least the glass gob velocity of the glass gob observationresult, a glass distribution of the glass product formed in the mould,and/or for controlling a next glass gob that is formed later than theglass gob.

It is another object of the invention to provide a system of an opticalimaging device and an apparatus for filling a mould with a glass gob,that enables an improved process control.

Thereto the invention provides a system comprising an optical imagingdevice, a signal processing unit coupled to the imaging device, and anapparatus for filling a mould with a glass gob through an opening of themould, for forming a glass product in the mould, the apparatus having adelivery system for delivering the glass gob to the opening of themould, the delivery system having an inlet, an outlet, and guiding meansfor guiding the glass gob through the delivery system towards the outletof the delivery system, wherein the optical imaging device is arrangedfor generating a signal representing an image of the glass gob at atleast one moment and/or during at least one period, after the glass gobhas passed the inlet of the delivery system, wherein the signalprocessing unit is arranged for determining, based on the signalrepresenting the image, a glass gob observation result that includes aglass gob velocity, and wherein the signal processing unit is arrangedfor predicting, based on at least the glass gob velocity of the glassgob observation result, a glass distribution of the glass product formedin the mould, and/or for generating a control signal for the apparatusfor controlling, based on at least the glass gob velocity of the glassgob observation result, depositing a next glass gob in the inlet of thedelivery system, guiding the next glass gob towards the outlet of thedelivery system, and/or depositing the next glass gob from the outlet ofthe delivery system in the opening of the mould. Deviation of the glassgob velocity, or equivalently a parameter representative therefore, froma predetermined value is a good indicator for loss of quality of theglass product, for example the degree of inclusion of gas in the glassproduct and/or a deviation of the external shape of the glass productfrom a predetermined external shape. As the system is arranged fordetermining the glass gob velocity, it enables an improved processcontrol.

In an embodiment, predicting the glass distribution includes predictingan internal structure and/or an external shape of the glass productformed in the mould. Preferably, predicting the internal structureincludes predicting a degree of inclusion of gas in the glass productand/or predicting the external shape includes predicting a deviation ofthe external shape of the glass product from a predetermined externalshape. These methods of predicting may be based on a magnitude of theglass gob velocity and/or a direction of the glass gob velocity.

Preferably, the apparatus has a mould holder for holding the mould belowthe outlet.

In an embodiment, the optical imaging device includes at least twocameras, each camera having an optical axis, wherein in use the opticalaxes of the at least two cameras have mutually distinct directions,preferably mutually transverse directions. The use of at least twocamera enables determining the glass gob velocity in three dimensions.

Preferably, in use the optical axes of the at least two cameras aredirected transverse to a travel path of the glass gob from the outlet tothe opening of the mould.

In an aspect of the invention, the glass gob observation resultassociated with the method of filling the mould with the glass goband/or associated with the system comprising the optical imaging deviceand the apparatus for filling the mould with the glass gob, includes atemperature and/or a temperature distribution of the glass gob. Thetemperature and/or the temperature distribution may be determined byusing one or at least two infrared cameras, which may be included by theoptical imaging device. Such infrared cameras may be arranged formeasuring radiant energy of the glass gob, which can be related to thetemperature and/or the temperature distribution of the glass gob. Thetemperature and/or the temperature distribution may be related tosubstantially the whole volume of the glass gob, or to a near-surfaceregion of the glass gob. The temperature and/or the temperaturedistribution strongly influences the viscosity of liquid materialforming the glass gob, which is an important parameter for filling themould. The temperature and/or the temperature distribution may deviatefrom a desired temperature or temperature distribution, for example as aresult of changes in time of processes during formation of the glassgob, or as a result of changes in time of heat loss of the glass gobtowards the guiding means. Such heat loss in general depends on thefriction of the guiding means, which friction may change in time.Determining the near-surface temperature and/or near-surface temperaturedistribution using the one or at least two infrared cameras forms anefficient way of measuring, as the near-surface temperature and/ornear-surface temperature distribution is most vulnerable for undesiredcooling, for example as a result of the heat loss. In addition,measuring the near-surface temperature offers the surprising advantagethat it provides important information for assessing the friction of theglass gob with the inner wall of the mould. As the viscosity of theliquid material forming the glass gob is strongly dependent ontemperature, the near-surface temperature of the glass gob largelydetermines the viscosity near the surface, and thus the friction of theglass gob with the inner wall of the mould. Such friction is importantfor the glass gob to travel far enough into the mould, and for theoccurrence of air inclusion in the glass product. Both of these arenegatively influence by the friction being too large. Use of the one orat least two infrared cameras in general shows the advantage ofcontactless temperature measurement.

As the temperature and/or the temperature distribution, and the glassgob velocity are important for predicting the glass distribution in themould, the inventor recognised the value of determining, based on theobserving in step d), a glass gob observation result that includes aglass gob velocity and a glass gob temperature and/or glass gobtemperature distribution, for predicting, based on at least the glassgob velocity and the glass gob temperature and/or glass gob temperaturedistribution of the glass gob observation result, a glass distributionof the glass product formed in the mould, and/or for controlling, basedon at least the glass gob velocity and the glass gob temperature and/orglass gob temperature distribution of the glass gob observation result,depositing as in step a), guiding as in step b), and/or depositing as instep c), of a next glass gob that is formed later than the glass gob.Such a combination of at the one hand the glass gob velocity and on theother hand the glass gob temperature and/or the glass gob temperaturedistribution, enables an improved predicting of the glass distributionand/or improved controlling of the next glass gob.

However, based on the above, the inventor also recognized the importanceof carrying out step d) and determining, based on the observing in stepd) a glass gob observation result that includes a glass gob temperatureand/or a glass gob temperature distribution, preferably by using one orat least two infrared cameras, without necessarily carrying out step a),b), and/or determining, based on the observing in step d), a glass gobobservation result that includes a glass gob velocity, for predicting,based on at least the glass gob velocity of the glass gob observationresult, a glass distribution of the glass product formed in the mould,and/or for controlling, based on at least the glass gob velocity of theglass gob observation result, depositing as in step a), guiding as instep b), and/or depositing as in step c), of a next glass gob that isformed later than the glass gob.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The invention will now be described, in a non-limiting way, withreference to the accompanying drawings, in which

FIG. 1A shows a system in a first embodiment according to the invention;

FIG. 1B shows a first and a second optical axis in a first planeperpendicular to a travel path of a glass gob;

FIG. 1C shows a first and a second optical axis in a second planeparallel with a travel path of a glass gob;

FIG. 1D shows a photo of glass gobs falling from an outlet towards anopening of a mould;

FIG. 2 shows a system in a second embodiment according to the invention;

FIGS. 3A-F show subsequent stages of a process for forming a glassproduct; and

FIGS. 4A-G show subsequent stages of an alternative process of forming aglass product.

DETAILED DESCRIPTION OF THE INVENTION

Unless stated otherwise, the same reference numbers refer to likecomponents throughout the drawings.

FIG. 1A shows a system 2 in a first embodiment according to theinvention. The system 2 comprises an optical imaging device 4, and anapparatus 6 for filling a mould 8 with a glass gob 10 through an opening12 of the mould 8. The apparatus 6, and the system 2, are arranged forforming a glass product in the mould, for example a bottle. Theapparatus 6 as such is known to the skilled person. The glass gob 10 maybe substantially made of inorganic material such as silicon oxide.

The apparatus 6 has a delivery system 14 for the glass gob 10. Thedelivery system has an inlet 16, an outlet 18, and guiding means 20 forguiding the glass gob 10 through the delivery system 14 towards theoutlet 18 of the delivery system 14. In the first embodiment, theguiding means 20 include a scoop funnel 22 that forms the inlet 16. Inaddition, the system 2 may include a trough 24 and a deflector funnel 26that forms the outlet 18. For formation of the glass gob 10, theapparatus 6 further may include a pair of shear blades 28 to detach theglass gob 10 from a glass column 30 pushed out of a reservoir of liquidglass through an orifice 32. The apparatus 6 may further include anaccelerator 34 for accelerating the formed glass gob. Such anaccelerator may accelerate the glass gob by applying air pressure on theglass gob. In addition, the accelerator in use may centralizes the glassgob. The accelerator as such is known to the skilled person.

The optical imaging device 4 may include at least two cameras, in thisexample a first camera 36A and a second camera 36B. The first and/orsecond camera may for example be a CMOS (complementarymetal-oxide-semiconductor) camera or a CCD (charge coupled device)camera, both known as such to the skilled person. The optical imagingdevice 4 may be arranged for generating a signal representing images ofthe glass gob 10, for example obtained by the first and second camera36A, 36B. Thereto the imaging device 4 may include a processor. Thefirst and second camera 36A, 36B individually may have respectively afirst optical axis 38A and a second optical axis 38B. FIGS. 1B and 1Cillustrate possible orientation of the first and second optical axis38A, 38B with respect to a travel path 40 of the glass gob 10. In use,the first and second optical axis 38A, 38B may have mutually distinctdirections.

FIG. 1B shows the first and the second optical axis 38A, 38B in a firstplane perpendicular to the travel path 40 of the glass gob 10. The firstand second optical axis preferably have mutually transverse directions.For example, in the first plane, a first angle α between the first andsecond optical axis is larger than 20 degrees and smaller than 340degrees. Preferably, the first angle α is near 90 degrees or near 270degrees. As a result, the first and second optical axis may havemutually perpendicular directions.

FIG. 1C shows the first and the second optical axis 38A, 38B in a secondplane parallel with the travel path 40 of the glass gob 10. The firstoptical axis preferably is transverse to the travel path 40. Forexample, in the second plane, a second angle β between the first opticalaxis 38A and the travel path 40 is larger than 20 degrees and smallerthan 160 degrees. The second optical axis preferably is transverse tothe travel path 40. For example, in the second plane, a third angle γbetween the second optical axis 38B and the travel path 40 is largerthan 20 degrees and smaller than 160 degrees.

With reference to FIGS. 1A-C there will be described a method of fillinga mould with a glass gob, in a first embodiment according to theinvention (hereafter referred to as the first method). The method isarranged for filling the mould 8 with the glass gob 10 through theopening 12 of the mould 8, for obtaining the glass product. The methodincludes using the delivery system 14 for delivering the glass gob 10 tothe opening 12 of the mould 8.

The first method includes depositing the glass gob 10 in the inlet 16 ofthe delivery system. Such depositing may include allowing the glass gob10 to fall into the inlet 16 after formation of the glass gob 10.Depositing may also include aligning a glass gob formation position andthe inlet.

The first method further includes guiding the glass gob 10 by using theguiding means 20 towards the outlet 18 of the delivery system 14. Duringguiding, the glass gob may accelerate under the influence of gravity.The shape of the glass gob 10 may change as well during guiding. Guidingmay increase an elongation of the glass gob 10. A plurality of glassgobs 10 may be formed at one and the same formation position, while theglass gobs are guided towards mutually distinct positions in differentmoulds 8. In this way a plurality of glass products can be formedsimultaneously. In this example, the orifice and/or shear bladepositions can be regarded as the formation position at which the glassgob is formed. Alternatively, an opening 42 of the accelerator 34 may beregarded as the formation position.

The first method may further include depositing the glass gob 10 fromthe outlet of the delivery system 14 in the opening 12 of the mould 8.Such depositing may be obtained by allowing the glass gob 10 to fallfreely into the opening 12 of the mould 8, after the glass gob haspassed the outlet 18. Depositing may also include aligning the outletand the opening 12 of the mould 8.

The first method further includes observing the glass gob 10 at at leastone moment and/or during at least one period after the glass gob 10 haspassed the inlet 16. For example, observing is carried out at a momentwhile the glass gob 10 is in the deflector funnel 26 or when the glassgob has partly passed the outlet 18. However, preferably observing theglass gob 10 is carried out at at least one moment and/or during atleast one period after the glass gob 10 has completely passed the outlet18 of the delivery system 2.

In general, observing may be continuous, i.e. each glass gob that passesthe inlet 16 is observed. Alternatively, observing may be intermittent,i.e. the glass gobs may be sampled, so that not every glass gob thatpasses the inlet 16 is observed.

In the first method, observing may be carried out by using the opticalimaging device 4, in this example including the first and second camera36A, 36B. Observing may be carried out with the first and second opticalaxis 38A, 38B of respectively the first and second camera 36A, 36Bhaving mutually distinct directions, preferably mutually transversedirections with the first angle α in a range from 20 to 160 degrees,optionally in a range from 50 to 130 degrees. Further, observing may becarried out with the second angle β and the third angle γ in a rangefrom 20 degrees to 160 degrees, optionally in a range from 50 to 130degrees. The first and second optical axis 38A, 38B are thus directedtransverse to the travel path 40 of the glass gob 10.

In general, it is recognized by the inventor that it is advantageous tohave, during observing, the second angle β and/or the third angle γlarger than 90 degrees, for example in a range from 110 to 170 degrees.This enables observation of the glass gob 10 in a downwardly inclineddirection. As a result, observation is not hindered by a frame of theapparatus 6 and/or by the mould 8. In addition, such observation may befacilitated by the first angle α being smaller than 190 degrees, forexample near 90 degrees, so that the first and second camera can beplaced at the same side of the mould 8.

In general, observing the glass gob 10 may include recording an image,preferably at least two images at different times, of the glass gob 10,by using the optical imaging device 4. The image may be recorded at theat least one moment. The at least two images may be recorded during theat least one period. The first and second camera may be high-speedcameras. Such a high-speed camera as such is known to the skilledperson. The high-speed camera may be able to record for example at least500 images per second. However, in other variations, the image or imagesare not necessarily recorded by the first and second camera.

The first method further includes determining, based on the observing instep d), for example based on the recorded images and/or based on thesignal representing the images, a glass gob observation result thatincludes a glass gob velocity. Thereto the system 2 may include a signalprocessing unit for calculating the glass gob velocity, for example fromthe recorded images. The signal processing unit is not shown in FIG. 1A,but is shown is FIG. 2 with reference number 44. Calculating the glassgob velocity may take into account the value of the first, second, andthird angle. Methods and algorithms for such calculating are known assuch to the skilled person, and a further description is deemedsuperfluous.

The first method may include using the determined velocity forpredicting, based on at least the glass gob velocity of the glass gobobservation result, a glass distribution of the glass product formed inthe mould, for example an internal and/or external shape of the glassproduct formed in the mould 8. Such predicting may include predicting adegree of inclusion of gas in the glass product and/or predicting adeviation of the external shape of the glass product from apredetermined external shape. The predetermined internal and/or externalshape is for example a shape within normal manufacturing specifications.Such manufacturing specifications may include, at various locationsalong the glass product, length dimensions of the glass product, such asan inner diameter and an outer diameter of a glass bottle. Themanufacturing specifications may also include a maximum diameter of agas bubble in the glass product and/or a maximum number of gas bubblesin the glass product, for example in a wall of the glass bottle. Themaximum diameter and the maximum number of gas bubbles are examples ofthe degree of inclusion of gas in the glass product.

FIG. 1D shows a photo of glass gobs 10 falling from the outlet 18towards the opening 12 of the mould 8, in this example two separateopenings 12 of two separate moulds 8. In this example, the deflectorfunnel is one of a plurality of deflector funnels forming the outlet 18.Each opening 12 forms an entrance to three positions 35 of the mould 8at which the glass product can be formed. The number of positions 35contained by one mould 8 may be equal to the number of the plurality ofdeflector funnels contained by the delivery system.

A second method, in a second embodiment according to the invention, mayinclude the steps of the first method. The second method is describedwith reference to FIGS. 1A-D. In the second method, the glass gobobservation result further includes at least one of a group of variablesincluding a glass gob trajectory, a glass gob shape, a change in theglass gob shape, a glass gob orientation, and a change in the glass goborientation, for assessing the degree of inclusion of gas in the glassproduct and/or for assessing the deviation of the shape of the glassproduct from the predetermined shape. The glass gob 10 may have anelongated shape, so that the glass gob has a longitudinal axis 37 (FIG.1D). Then, the orientation of the glass gob is determined by a directionof the longitudinal axis 37. The glass gob trajectory may be part of thetravel path 40 of the glass gob 10. The change in the glass gob shapeand/or the change in the glass gob orientation may refer to a changefrom one glass gob to a subsequent glass gob at substantially the sameposition, may refer to a change of one and the same glass gob, or mayrefer to a change from one glass gob to another glass gob at mutuallydifferent position, to be deposited at different part of the mould 8.

In general, the glass gob velocity is preferably determined in threedimensions, so that the glass gob velocity is a three-dimensional glassgob velocity. The glass gob trajectory may be a three-dimensional glassgob trajectory, the glass gob shape may be a three-dimensional glass gobshape, the change in the glass gob shape may be a change in thethree-dimensional glass gob shape, the glass gob orientation may be athree-dimensional glass gob orientation, and the change in the glass goborientation may be a change in the three-dimensional glass goborientation. Such three-dimensional variables enable a more reliableprocess control.

In the second method, observing in step d) may be carried out before theglass gob 10 has entered the opening 12 of the mould 8. In addition,observing in step d) is carried out with the glass gob being positionedin proximity of the mould, for example within one, two, or three times adimension of the glass gob. Such a dimension may be a length of theglass gob along the longitudinal axis. Observing the glass gob inproximity of the mould before the glass gob has entered the mould maygive the user sufficient space for observation, while the observation isrepresentative for the properties, such as the glass gob velocity, ofthe glass gob when it enters the mould.

FIG. 2 shows a system 2 in a second embodiment according to theinvention. The system 2 in the second embodiment includes the scoopfunnel 22, the trough 24, and the deflector funnel 26. The system 2 mayfurther include the optical imaging device 4 and the signal processingunit 44. The optical imaging device 4 may be connected to the signalprocessing unit 44 for transmission of the signal representing the imagefrom the optical imaging device 4 to the processing unit 44. The signalprocessing unit 44 may be arranged for predicting, based on at least theglass gob velocity, a glass distribution of the glass product formed inthe mould.

The signal processing unit 44 may be arranged for generating a controlsignal for the apparatus for controlling, based on at least the glassgob velocity of the glass gob observation result, guiding the next glassgob. Such controlling may include adjusting lubrication of the guidingmeans, in this example the scoop funnel 22, the trough 24, and/or thedeflector funnel 26. Thereto the system 2 may include lubrication means46, that are in use controlled by the signal processing unit 44 viaconnections 48 through which the control signal for controlling guidingmay be transmitted to the lubrication means 46. Hence, the first signalprocessing unit 44 may be coupled to the lubrication means 46 and theoptical imaging device 4. The signal processing means 44 may be formedby a computer with, in use, controlling software and/or predictionsoftware running thereon. Based on the glass gob observation result, thesignal processing unit 44 in use may adjust the lubrication of theguiding means 20. For example, if the magnitude of the velocity of theglass gobs 10 decreases below a predetermined limit value, the signalprocessing unit 44 may give to the lubrication means 46 a command fordispending lubricant onto the guiding means 20, so that a resistance ofthe glass gob 10 in the guiding means is decreased. As a generaladvantage, the system 2 enables automatic lubrication of the guidingmeans.

The signal processing unit 44 may be arranged for generating a controlsignal for the apparatus for controlling, based on at least the glassgob velocity of the glass gob observation result, depositing the nextglass gob. Thereto the system 2 may include displacement means 52coupled to the signal processing unit 44 via connections 50 throughwhich the control signal for controlling depositing may be transmittedto the displacement means 52. Such controlling may include adjusting amutual position difference of the inlet and a formation position atwhich the glass gob is formed by means of the displacement means 52.Alternatively or additionally, controlling may include adjusting amutual position difference of the outlet 18 and the opening of themould, by using the displacement means 52.

In general, the scoop funnel may be one of a plurality of scoop funnels.The trough may be one of a plurality of troughs. The deflector funnelmay be one of the plurality of deflector funnels. Guiding the glass gobmay include guiding the glass gob by means of the one of the scoopfunnels towards the one of the troughs, and may further include guidingthe glass gob by means of the one of the troughs towards one of thedeflector funnels.

The system 2 may include adjustment means 60 coupled to the signalprocessing unit 44 via connections 62 through which the control signalfor controlling guiding may be transmitted to the adjustment means 60.Controlling guiding the next glass gob may include adjusting a mutualposition of at least two of the scoop funnel, the one of the troughs andthe one of the deflector funnels by using the adjustment means. As ageneral advantage, the system 2 enables automatic adjustment of theguiding means 20.

The first and/or second method may include using the glass gobobservation result for controlling forming of a next glass gob that isformed later than the glass gob 10. Such controlling may includeadjustment of a moment at which the shear blades 28 cut the glass thatflows out of the orifice 32, and/or adjustment of a force with which theshear blades cut the glass that flows out of the orifice 32.Alternatively or additionally, such controlling may include adjustmentof a force and/or a velocity with which the glass is pushed out of theorifice 32.

The first and/or second method may include using the glass gobobservation result for controlling, based on at least the glass gobvelocity of the glass gob observation result, guiding the next glassgob, by using the guiding means, towards the outlet of the deliverysystem. This controlling may include adjusting lubrication of theguiding means. This can be achieved by using the signal processing unit44 and the lubrication means 46 of the system 2 in the secondembodiment.

In general, the first and/or second method may include aligning theoptical imaging device 4, in particular the first and/or second camera36A, 36B with respect to the mould. In this way, the direction of theglass gob velocity with respect to the mould, in particular the openingof the mould, can be inferred from the glass gob observation result.

The first and second method may include using the glass gob observationresult for controlling, based on at least the glass gob velocity of theglass gob observation result, deposition of the next glass gob. Thiscontrolling may include adjusting a mutual position difference of theinlet 16 and a formation position at which the next glass gob is formedand/or includes adjusting a mutual position difference of the outlet 18and the opening 12 of the mould 8. This can be achieved by using thesignal processing unit 44 and the displacement means 52 of the system 2in the second embodiment.

The first and second method may include using the glass gob observationresult for controlling, based on at least the glass gob velocity of theglass gob observation result, guiding the next glass gob, by using theguiding means, towards the outlet of the delivery system. Thiscontrolling may include adjusting a mutual position of at least two ofthe one of the scoop funnels, the one of the troughs and the one of thedeflector funnels. Adjusting the mutual position of the one of thetroughs and the one of the deflector funnels can be achieved by usingthe signal processing unit 44 and the adjustment means of the system 2in the second embodiment.

The first and/or second method may include determining the glass gobobservation result for a plurality of glass gobs, and comparing betweenthe plurality of glass gobs the glass gob observation results. Comparingmay be between glass gobs deposited from one and the same outlet 18.This supports the process control in that differences, for examplechanges in time, in the glass gob observation result can be detectedfrom one glass gob to another glass gob. If such changes are detected,process control may be applied, for example adjusting a mutual positiondifference of the inlet and the formation position at which the nextglass gob is formed, adjusting a mutual position of at least two of theone of the scoop funnels, the one of the troughs, and the one of thedeflector funnels by using the adjustment means, and/or adjustinglubrication of the guiding means.

The first and/or second method may be applied during production of theglass product, or during start-up and/or calibration of the apparatus 6.

FIGS. 3A-F show subsequent stages of a process for forming the glassproduct, in this example the bottle 72 of FIGS. 3E and 3F. Anotherexample of the glass product is for example the preform 74 of FIGS. 3Cand 3D. FIG. 3A shows the glass gob 6 entering the mould 8 through themould opening 12. FIG. 3B shows the glass material 76 of the glass gob10 being blown downwards by using air pressure. FIG. 3C shows the glassof the glass gob 10 after air is blown upwards from air opening 78, thusforming the preform 74. In a subsequent step, the preform 74 is turned180 degrees, in order to obtain an orientation of the preform 74 shownin FIG. 3D. By blowing air into the preform, the glass product 72 isobtained, as shown in FIG. 3E. After removing the mould 8, for exampleby separating and moving away a first part and a second part of themould 8, the bottle 72 is obtained, as shown in FIG. 3F. In a method ina third embodiment according to the invention, these stages may beincluded.

FIGS. 4A-G show subsequent stages of an alternative process of formingthe glass product, in this example the glass bottle 72 or the preform74. FIG. 4A shows the glass gob 6 entering the mould 8 through the mouldopening 12. After entering, the opening 12 of the mould 8 may be closedand a moulding element 80 may be pushed into the material 76 of theglass gob 10, shown in FIGS. 4B and 4C. In this way the preform 74 maybe manufactured. The preform 74 is subsequently inverted by using theinverter 82, along the arrow 84, as shown in FIG. 4D. A part 86 of themould 8 may be removed, to expose the preform 74, as shown in FIG. 4E.After blowing air into the preform (FIG. 4F), the glass product, in thisexample the glass bottle 72, may be obtained after removing the mould 8(FIG. 4G). In a method in a fourth embodiment according to theinvention, these stages may be included.

Although also advantageous in the fourth method, determining the glassgob velocity for predicting the glass distribution in the mould and/orfor controlling the next glass gob is even more advantageous in thethird method. In the third method, the glass product is more sensitiveto increased friction of the glass gob in the mould, as use of themoulding element 80 is missing in the third method.

The method in the first, second, third, or fourth embodiment may have afeature that is not described for that embodiment, but is described foranother one of the first, second, third, or fourth embodiment. Theinvention is not limited to any embodiment herein described and, withinthe purview of the skilled person, modifications are possible which maybe considered within the scope of the appended claims. Equally allkinematic inversions are considered inherently disclosed and to bewithin the scope of the present invention. The use of expressions like:“preferably”, “in particular”, “especially”, etc. is not intended tolimit the invention. The indefinite article “a” or “an” does not excludea plurality.

Thus, although there have been described particular embodiments of thepresent invention of a new and useful Method of filling a mould, andsystem for filling a mould it is not intended that such references beconstrued as limitations upon the scope of this invention except as setforth in the following claims.

What is claimed is:
 1. Method of filling a mould with a glass gobthrough an opening of the mould, for forming a glass product in themould, by using a delivery system for delivering the glass gob to theopening of the mould, the delivery system having an inlet, an outlet,and guiding means including at least one of a funnel or a trough forguiding the glass gob through the delivery system, the method includingthe steps: a) depositing the glass gob in the inlet of the deliverysystem; b) guiding the glass gob by using the guiding means towards theoutlet of the delivery system; c) depositing the glass gob from theoutlet of the delivery system in the opening of the mould; d) observingthe glass gob, at at least one moment and/or during at least one periodafter the glass gob has passed the inlet of the delivery system, byusing an optical imaging device; e1) determining, based on the observingin step d), a glass gob observation result that includes a glass gobvelocity, for; and e.2) controlling, using a predetermined relationbetween glass gob velocity and a distribution of the glass productformed in the mould according to at least the glass gob velocity of theglass gob observation result, at least one of the depositing as in stepa), the guiding as in step b), or the depositing as in step c), of anext glass gob that is formed later than the glass gob, wherein theglass gob observation result further includes a group of variablesincluding a glass gob trajectory, a glass gob shape and a glass goborientation wherein controlling in step e) is further based on thesevariables.
 2. Method according to claim 1, wherein the glass gobvelocity includes a magnitude of the glass gob velocity.
 3. Methodaccording to claim 1, wherein the glass gob velocity includes adirection of the glass gob velocity.
 4. Method according to claim 1,wherein the glass gob observation result further includes at least oneof a second group of variables including a change in the glass gobshape, and a change in the glass gob orientation, and whereincontrolling in step e) is further based on the at least one variable ofthe second group.
 5. Method according to claim 1, wherein observing instep d) is carried out at at least one moment and/or during at least oneperiod after the glass gob has, at least partly and optionallycompletely, passed the outlet of the delivery system.
 6. Methodaccording to claim 1, wherein observing in step d) is carried out at atleast one moment and/or during at least one period after the glass gobhas, at least partly, entered the opening of the mould.
 7. Methodaccording to claim 1, wherein the optical imaging device includes atleast two cameras, each camera having an optical axis, wherein observingin step d) is carried out with the optical axes of the at least twocameras having mutually distinct directions, preferably mutuallytransverse directions.
 8. Method according to claim 1, wherein the glassgob velocity is a three-dimensional glass gob velocity.
 9. Methodaccording to claim 1, including the steps: f) forming the glass gob, bydetaching the glass gob from a liquid glass reservoir; and g) using theglass gob observation result for controlling forming the next glass gobthat is formed later than the glass gob formed in step f).
 10. Methodaccording to claim 9, wherein controlling in step g) is based on atleast the glass gob velocity of the glass gob observation result. 11.Method according to claim 1, wherein controlling, in step e), of guidingas in step b) of the next glass gob includes adjusting lubrication ofthe guiding means.
 12. Method according to claim 1, wherein controlling,in step e), of depositing as in step a) of the next glass gob includesadjusting a mutual position difference of the inlet and a formationposition at which the glass gob is formed.
 13. Method according to claim1, wherein controlling, in step e), of depositing as in step c) of thenext glass gob includes adjusting a mutual position difference of theoutlet and the opening of the mould.
 14. Method according to claim 1,wherein the guiding means include a scoop funnel forming the inlet, atrough, and a deflector funnel forming the outlet, wherein guiding theglass gob in step b) includes guiding the glass gob by means of thescoop funnel towards the trough, and further includes guiding the glassgob by means of the trough towards the deflector funnel, and whereindepositing the glass gob in step c) includes depositing the glass gob bymeans of the deflector funnel in the opening of the mould, whereincontrolling, in step e), of guiding as in step b) of the next glass gobincludes adjusting a mutual position of at least two of the scoopfunnel, the trough, and the deflector funnel.
 15. Method according toclaim 1, wherein controlling, in step e), of depositing as in step a) ofthe next glass gob includes adjusting air supply to an accelerator forthe next glass gob, which accelerator is positioned before the inlet.16. Method according to claim 1, including repeating steps a)-e) for aplurality of glass gobs.